Chromium-steel alloy



Patented Apr. 8, 1924.

" UNITED STATES PATENT OFFICE.-

IBERTON H. DE LONG, OF SPRINGMONT, SINZ KING SPRING, AND FRANK R. PALMER, F

READING, PENNSYLVANIA, ASSIGNO'RS TO THE CARPENTER STEEL COMPANY, OF

READING, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

'10 Drawing.

To all whom it may concern:

Be it known that we, BERTON H. De Lone and FRANK R. PALMER, citizens of the United States, residing, respectively, at

Springmont, Sinking Spring P. 0., and Reading, in the county of Berks and State of Pennsylvania, have invented certain new and use ul Improvements in Chromium- Steel Alloys, of which the following is a specification.

. Our invention relates to steel alloys characterized b a considerable chromium content, and t e main object is to provide for securing the maximum of known advantages incident to the use of chromium while at the same time eliminating or reducing known disadvantages and giving added desirable quality to-the product. To this end the invention consists essentially in emplaying copper as an alloy element in connection with the chromium and with carbon, as fully set forth hereinafter and clearly defined ,in the claims.

The type analysis of our improved allo as most satisfactorily tested particular y for the purposes hereinafter specifically referred to may be stated as follows; it being understood that the ferrous base employed may be of any ordinary commercial content without essentially aifecting the results attained; to wit:

Carbon 40% Chromium 20. 00% Copper 1t 00% In our further combined use of the alloying elements above noted, we have discovered that the proportions stated as typical may be varied, with corresponding variation of the characteristic results in all cases secured, within the following limits,

to wit:

Carbon, from .05% to 3.50%. Chromium, from 8.00% to 60.00%. Copper, from .50% to 10.00%. The desirability of a non-corrosive or "corrosion-resisting alloy steel is well understood; .and the effects of chromium in this direction have been recognized, and said element used in difierent proportions and in connection with carbon, particularly for a hardened product adapted for cutlery and facture composed of malleable ferrous alloy Application filed August 8, 1921f Serial No 490,383.

other cutting tools. The use of large percentages of chromium however have been attended by well known incidental disadvantages, and the carbon content tends to impair the surface resistance to deterioration attainment of-which is the main purpose We have in view. Wehave discovered that the employment of copper as stated, in connection with these elements, enables the overcoming of the disadvantages otherwise incident to desired use of the chromium and carbon'elements, and particularly that it enables the production of a readily malleable alloy having high surface resistance to cor-' rosion or deterioration irrespective of hardening of the surface, and of desired uniform texture and quality. The percentage of copper employed, relative to the percentages of chromium and carbon and of the ferrous base, ma be varied within the limits above state with substantial attainment of the desired non-corrosive effect and corresponding variations in specific structure and quality; approximately the rela-' tive proportions definitely stated above however having been found most satisfactory for ordinary uses of an unhardened .forgeable and corrosion-resisting alloy steel, though the essential corrosion-resisting quality is desirably imparted by the copper element within a range of constituent elements which would exclude the forgeable quality specifically provided for. .85

at we claim is:

1. A corrosion-resisting article of manufacture composed of a ferrous alloy containing chromium between eight per cent (8%) and sixty per cent (60%), carbon not in excess of three and one-half per cent (3.5%) and between one-half per cent (5%) and ten per cent (10%) of copper.

2. A corrosion-resisting article ofmanucontaining approximately twenty per-cent (20%) of chromium, four tenths per cent (40%) of carbon, and one per cent (1%) of copper.

In' testimony whereof we afix our signatures BERTON H. DE LONG. FRANK R. PALMER. 

